Revised immerSUN Monitoring

I have re-worked the monitoring solution for the immerSUN solar PV diverter which is responsible for measuring the house’s electricity consumption, the import of electricity from the grid, the solar PV generation and any diversion of excess solar generation to the domestic hot water cylinder’s immersion heater.

Previously the monitoring was done by extracting data from the webpage every minute and storing it in InfluxDB for visualization using Grafana. This worked OK but missed a lot of the details of how the readings change on a more dynamic basis. The immerSUN unit actually sends data in the form of a 56-byte UDP Datagram every 5 seconds and since this data is traversing the local network anyway it seems a shame not to extract the readings “on the way past”. While not trivial, since the format of the 56-byte Datagram is not published, it’s not that hard to reverse engineer where the different readings are.

There’s a (draft) write-up of the solution under the Technical Articles here.

Broadcast TV over CAT6 Cable

On reflection it would have been a sensible idea to run some good-quality coaxial cable from the comms room to the likely locations of TVs around the house. While video transmission is definitely moving towards Internet streaming services you still get a more seamless viewing experience when you can provide a TV with a good aerial signal.

In particular, it was surprising to find that the ‘All 4’ catch-up app on Android TV needed to be enabled via the YouView setup process – which insists on seeing an aerial, albeit only temporarily.

There are two CAT6 cables running from the comms room to all the likely TV locations, so one of those provides a wired Internet connection and there’s a second one available for other purposes.

While the high frequencies of broadcast television present something of a challenge, using a pair of high quality baluns it’s perfectly feasible to distribute a TV aerial signal over 50 or so metres of CAT6 cable. MuxLab from Canada offer a range of baluns and their CATV units are rated up to 900MHz. They offer shielded and unshielded variants. In the UK they’re available from CPC Farnell and other similar distributors.

MuxLab Shielded CATV Baluns

It’s pretty much essential to use an amplifier to help offset the inevitable loss of signal strength. This one from Labgear works well.

Labgear LDA102R Signal Booster